Ms Griffiths has faced a barrage of questions over the e-mails sent by Prof Longley, who also faced the cross-party Health and Social Care Committee yesterday.

Prof Longley’s report, published in May, warned that some services were in danger of collapsing without reforms and put forward a case for removing some services from smaller hospitals in favour of creating regional centres of excellence.

But embarrassing e-mails have since emerged which show him asking civil servants for “killer facts” in order to strengthen the case.

Today, however, Ms Griffiths said it was “entirely appropriate” for civil servants to be in contact with Prof Longley.

“I want to be very clear. It was entirely appropriate for my officials to engage with Prof Longley,” she told AMs.

“I knew they were doing that. It was completely routine, but I was not overseeing it.

“I didn't collude, I didn't assert any influence, and neither did my officials.”

NHS medical director Dr Chris Jones, who was also giving evidence and whose e-mails to and from Prof Longley had been under close scrutiny, said the comments of opposition parties had been extremely difficult.

“As a doctor, the last few days have been quite painful because I have had to hear a lot of statements made in public about conniving, conspiracy, some sort of immoral behaviour, seeking to mislead the public,” he said.

“Now as a doctor, that's accusing me of serious professional misconduct, and that is very difficult for me.”

Prof Longley himself told the committee the criticism had “become personal” and that he had been “smeared by one or two people”.

The opposition case suffered as former Plaid Cymru president Lord Elis-Thomas stayed away from the vote and criticised his party for getting involved.

In comments seized on with glee by Carwyn Jones, he said: “I think Plaid has put itself in a position of being the supporting cast to a play which is produced by the Welsh Conservatives and that gets under my skin.

“This whole debate that’s taking place this afternoon is a debate which puts prejudice before evidence and I don't want to be part of such discussions.”

Following the vote, Shadow Health Minister Darren Milla insisted serious questions remained over Ms Griffiths and the report’s independence.

WalesOnline is part of Media Wales, publisher of the Western Mail, South Wales Echo, Wales on Sunday and the seven Celtic weekly titles, offering you unique access to our audience across Wales online and in print.